Need to securely automate SSH authenticity checking

Currently pool_create playbook provisions hosts and provides ssh keys to reach them.  Initially these hosts are unknown, thus ssh does host checks which requires user interaction and usually would happen during pool_install playbook. It is not the desired behavior and should be automated in a secure way. 

 Useful links:

• https://stackoverflow.com/questions/32297456/how-to-ignore-ansible-ssh-authenticity-checking
• https://stackoverflow.com/questions/23074412/how-to-set-host-key-checking-false-in-ansible-inventory-file
• https://docs.ansible.com/ansible/latest/user_guide/intro_getting_started.html#host-key-checking
• https://man.openbsd.org/ssh-keyscan
• https://blog.0xbadc0de.be/archives/300